Posting devices, as they are referred to, are utilized in orthopaedic surgery as devices on which sutures are tightened for the fixed tensioning and holding of such sutures, as may be required in various orthopaedic procedures such as with bone grafts. The posting devices are generally configured in the form of nails or screws, with head elements similar to those of standard screws and nails, and the posting devices are used with separate washer elements.
In use, the nail-configured posting devices are driven into a bone by impacting, such as with a driver. Posting devices, in the form of a screw, are rotatably inserted with a screw driver. In each embodiment the posting device is not initially completely seated so that suture can be engaged with or wrapped around under the head of the device and tensioned such as by pulling on the suture until a desired tension is reached. The suture is then fixed onto the posting device, against loosening, by the continued driving or screwing of the device into the bone until the wrapped suture is compressingly held between the nail or screw head and the washer used therewith.
There are several problems inherent with such posting devices, foremost of which is the difficulty of wrapping or tightening a suture against a screw or nail with only a minimal portion thereof extending over a bone surface for engagement with the suture material. An additional problem is that of gradual loosening of the tensioned posting device and suture, over extended periods of time, particularly with respect to the nail-like drive-in device with minimal frictional contact between bone and smooth nail shank surface.